Who Invented the Hydrometer | History of Hydrometer

The Banu Musa brothers, Ahmad, Muhammad, and Al-Hasan, were three Persian scholars and polymaths who lived in the 9th century. They made significant contributions in the fields of astronomy, engineering, mathematics, and medicine. 

The Banu Musa brothers were known for their contributions to the field of engineering, and one of their most notable inventions was the hydrometer. A hydrometer is an instrument used to measure the specific gravity of liquids, which can indicate the concentration of dissolved substances in the liquid.

The brothers described the use of a hydrometer in their book "Book of Ingenious Devices," which was written in the 9th century. In the book, they explained how to construct the hydrometer and how to use it to measure the specific gravity of liquids. 

The Banu Musa brothers' hydrometer consisted of a float with a weight attached to it. The float was placed in the liquid being measured and the specific gravity was determined by the depth to which the float sank.They also described how to use the hydrometer to measure the purity of liquids like wine, vinegar and others. The device was simple, yet effective and was used by many people over the centuries.

It is important to note that the Banu Musa brothers' invention of the hydrometer was not the first, but rather an improvement of an already existing instrument. Their work on hydrometer was translated and studied in Europe centuries later, and it helped to refine the instrument.